The invention is related to the display of images on a display screen of a portable computing device. More specifically, the invention is related to systems and methods for switching an orientation of images appearing on a display screen of a portable computing device when an orientation of the portable computing device itself is changed.
Portable computing devices, such as smart phones, typically include a display screen. Many portable computing devices are configured such that an orientation of the images that appear on the display screen can change when an orientation of the portable computing device itself changes.
FIGS. 1A and 1B illustrate a smart phone 100 in first and second orientations, respectively. The smart phone 110 includes a speaker aperture 140 towards one end of the smart phone 110 which is located so that it will be adjacent a user's ear when the smart phone 110 is held adjacent to one side of a user's head during a telephone call. A control button 130 is located at the other end of the smart phone 110. A display screen 120 is located between the speaker aperture 140 and the control button 130.
FIGS. 1A and 1B depict an e-mail message on the display screen 120 of the smart phone 110. When the smart phone 110 is in a first orientation, as illustrated in FIG. 1A, the e-mail message appears on the display screen 120 in a first orientation. When the smart phone 110 is rotated 90° counterclockwise to a second orientation, a display unit of the smart phone 110 causes the image of the e-mail message to appear on the display screen 120 in a second orientation. This change in the orientation of the image appearing on the display screen 120 is made to help a user to view the image. The assumption is that the user will find it easier to view of the image if the image is always orientated the same way, regardless of the orientation of the smart phone 110 and its associated display screen.
One or more orientation sensors in the smart phone 110 sense when the orientation of the smart phone 110 changes from the first orientation illustrated in FIG. 1A to the second orientation illustrated in FIG. 1B. When the orientation sensor(s) detect the change in orientation of the smart phone, a display unit of the smart phone 110 causes the images appearing on the display screen 120 to change from the first orientation illustrated in FIG. 1A to the second orientation in FIG. 1B.
There is typically a small time lag between the time that the orientation of the smart phone 110 changes and the time that the display unit causes the orientation of the images on the display screen 120 to change. This delay can be due, at least in part, to the time required for the orientation sensor(s) to detect and register the change in orientation of the smart phone 110, and for this information to be passed along to the display unit. Also, the display unit itself may require some time to cause a corresponding change in the orientation of the images on the display screen 120.
Because there are a wide range of tilted positions at which the smart phone 110 could be held by a user between the orientation illustrated in FIG. 1A and the orientation illustrated in FIG. 1B, the orientation sensor(s) are typically designed to report a change from the first orientation to the second orientation only after the smart phone 110 has been rotated a predetermined number of degrees counterclockwise from the position illustrated in FIG. 1A. This predetermined number of degrees could be 45°, or some other amount. Likewise, when the smart phone starts in the position illustrated in FIG. 1B and begins to rotate clockwise, the orientation sensor(s) are typically configured to report a change from the second orientation back to the first orientation only after the smart phone has rotated a predetermined number of degrees clockwise.
If a user is holding the smart phone 110 while moving, such as while walking, jogging, or perhaps riding in a vehicle, the user may end up holding the smart phone 110 in a tilted position that approaches the point at which the orientation sensor(s) will register a change from one orientation to the next. Continued movement can cause the user to frequently tilt the smart phone 110 back and forth past the point at which the orientation sensor(s) report changes between first and second orientations. When this occurs, the display unit may cause the images being displayed on the display screen 120 to rapidly switch back and forth between the first and second orientations. This makes it difficult for the user to view and/or read to the images on the display screen 120.